I do not think the “nightshot” mode is what You want for pictures at a houseparty. “Nightshot” mode is an IR mode, everything shows up in “green-scale”. “Nightshot mode is great for outdoors wildlife shots. The 707/717 also has a “nightframing” mode were You can setup the picture in IR and then take a normal flash picture; a good mode for flash pictures in total darkness. What the 707/717 does have is “Laser Hologram AF” it works very well, and makes Auto Focus in low light almost fool proof. The “Laser Hologram AF” can be set to work in all modes.

The Sony 717 has a 800 ISO, the higher the ISO the greater the amount on noise. There are ways of dealing with noise, but I’m not sure You are stating that You want to do that post production work.

Both the Sony 707/717 and the Fuji 602 are both very good. I would add that most people either love or hate the 707/717 there is little middle ground. I hope this helps.